vsftpd: 500 OOPS: prctl PR_SET_SECCOMP failed

It can happen when your kernel does not have the CONFIG_SECCOMP_FILTER enabled. But that can hardly change while you «work on website».

As a poor workaround, you can configure vsftpd not to enable the the seccomp mode.

Use the seccomp_sandbox=no option in the vsftpd.conf.

The option does not seem to be documented.